1. Field of the Invention
The invention relates to an electronic device case, and more particularly to an electronic device case for a rack server or a blade server.
2. Description of the Related Art
In a rack server or a blade server, multiple host computers are disposed in a cabinet for centralized management. Compared with a conventional pedestal server, the rack server or the blade server occupies a relatively smaller space. Components of the rack server or the blade server, such as a motherboard and a hard disk, are disposed in an elongated case that facilitates removal of these components. The case is enclosed by a top cover for protecting the components of the rack server or the blade server disposed in the case. Since replacement of a component of the rack server or the blade server requires removal of the top cover from the case, the top cover of the case needs to be installed and removed conveniently and not detached from the case unexpectedly.
Referring to FIG. 1, a conventional engaging mechanism 13 for locking a top cover 11 to a case 12 includes a latch 14 disposed on of the top cover 11, and a barb 15 disposed above a recess 122 in a side wall 121 of the case 12. The recess 122 has an opening 123 adjacent to the barb 15. When it is desired to lock the top cover 11 to the case 12, the latch 14 is moved into the recess 122 through the opening 123, and then, the latch 14 is pressed downwardly and the top cover is pushed horizontally toward a left direction of FIG. 1. As a result, the latch 14 is moved to and engages a left side of the barb 15. When it is desired to remove the top cover from the case 12, the latch 14 is pressed downwardly so as to disengage from the barb 15, and then, the top cover is pulled toward a right direction of FIG. 1 so as to remove the latch 147 from the recess 122 through the opening 123.
Referring to FIG. 2, since the latch 14 compactly contacts the barb 15 at a right-angled corner of the barb 15, a friction force between the latch 14 and the barb 15 is relatively great. Accordingly, when the latch 14 is pressed for removing the top cover from the case 12, the latch 14 and the barb 15 may generate noise and may be worn due to the friction force therebetween.
Therefore, in order to solve the above drawbacks, there is provided another conventional engaging mechanism 13 as shown in FIG. 3. A latch 16 of the engaging mechanism 13 of FIG. 3 has a curved end in contact with the barb 15. Thus, contact area between the latch 16 and the barb 15 is reduced, and a friction force therebetween is reduced accordingly. However, when the latch 16 is located at the left side of the barb 15 and engages the barb 15, the latch 16 abuts against the barb 15 and a reaction force from the barb 15 generates a torque exerting on the latch 16 as shown by a clockwise arrow in FIG. 3 while the top cover is forced by an external force to move toward a right direction of FIG. 3 without pressing the latch 16. At this time, since the end surface of the latch 16 is curved and results in a relatively small friction force, the latch 16 may easily move downwardly relative to the barb 15 due to the torque and may even move past the barb 15 to unexpectedly release the top cover.